The best Brago lists are probably those build around stax pieces - Stasis, Static Orb etc. - using his blink on mana rocks to untap them and thus break the symmetry of the stax effects, while building towards a Strionic Resonator win. Here's a list to have a look over.
Hehe, yeah, I hadn't actually looked at quite how much that list cost, it is a little excessive. Still, the basic idea behind the deck could be built on a much more sensible budget - cut out the Timetwister, the more expensive parts of the manabase (Tundra...) and the pricey rocks (Mox Diamond, Mana Crypt etc.) and a few other things like Mana Drain and Transmute Artifact and it looks a lot more reasonable.
Assuming that your playgroup are all avoiding very expensive cards, then an effective list built around the same principle of getting the strong stax pieces out with a good amount of artifact mana to make them asymmetric is likely to be pretty affordable - you can get by with a good amount of the CMC2/3 rocks if you don't need to be competing with decks that are trying to win turn 3/4, there are some reasonably priced tutors like Fabricate and the lockdown effects aren't too pricey.
Just in case you're not aware of the website EDHREC https://edhrec.com/commanders/brago-king-eternal, it has a break down of cards from deck submissions and the cool thing is that it has the prices for the cards so you'll be able to ascertain what you can afford. Honestly it's hard not to make a good Brago deck, as long as he is attacking you're normally winning. Not attacking, losing(ish). Forget Stax, it's a million dollars, just go for card advantage, via repeatable removal and draw, and make sure you have the ability to cast cards with some reusable mana with mana rocks.
Assuming that your playgroup are all avoiding very expensive cards, then an effective list built around the same principle of getting the strong stax pieces out with a good amount of artifact mana to make them asymmetric is likely to be pretty affordable - you can get by with a good amount of the CMC2/3 rocks if you don't need to be competing with decks that are trying to win turn 3/4, there are some reasonably priced tutors like Fabricate and the lockdown effects aren't too pricey.
Niv-Mizzet Reborn
Feather, the Redeemed
Estrid, the Masked
Teshar
Tymna/Ravos
Najeela, Blade-Blossom
Firesong & Sunspeaker
Zur the Enchanter
Lazav, the Multifarious
Ishai+Reyhan
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-Prime Speaker Vannifar
---------------------Will & Rowan Kenrith